/Engine/Source/Runtime/Engine/Public/AnimationRuntime.h
Utility for taking an array of bone indices and ensuring that all parents are present (ie. all bones between those in the array and the root are present). Note that this must ensure the invariant that parent occur before children in BoneIndices.
static void EnsureParentsPresent ( [TArray](API\Runtime\Core\Containers\TArray)< FBoneIndexType > & BoneIndices, const [FReferenceSkeleton](API\Runtime\Engine\FReferenceSkeleton) & RefSkeleton )